You can try the following to check the deflection results in tabular format. But you need to use STAAD.Pro SS6 version (like latest build 20.07.11.50).
1. Create unfactored load combination cases.
2. Create a load envelope with type Serviceability (say Envelope 1) and add the unfactored load combinations to this load envelope.
3. Add LOAD LIST ENVELOPE 1 command before the design PARAMETER command.
4. Add only DFF and DJ parameters and CHECK CODE command.
Program will perform only the deflection check and you can get the deflection check results in the post-processing > Unity check table as shown in the following figure--
